Directive antenna system



March 26, 1940. M, KAT-2m 7 2,194,554

DIRECTIVE ANTENNA SYSTEM Filed April 8, 1938 3 Sheets-Sheet 1' 70RECEIVER 170 RECEIVER 4 *2 .3 3 J L L- v/ INSULATOR INVENTOR.

MART/N KA TZ/N p t Mob ATTORNEIC March 26, 1940.

DIRECTIVE ANTENNA SYSTEM Filed April 8, 1938 3 Sheets-Sheet 2 Fl y. 4

r0 RfCf/VER r0 RECEIVER INVENTOR.

MARTfNZATZ/N BY '2 g Afrromvzy.

M. KATZIN 2,194,554

March 26, 1940. K T N 4 2,194,554

DIRECTIVE ANTENNA SYSTEM Filed April 8, 195a 3 Sheets-Sheet s ITORECE/VER .2 I 2 I I I I r0 RECEIVER 7 2 2 x r "QN I" I i I r 4 1 2 x I2 2 "I & f 2 I INVENTOR. MART/N KATZ/N BY ATTORNEY.

soiFebruary 12, 1936, by H; 0. Peterson and'assigned 35stenna conductorsso that the velocityof cur- 45Yle'ad of the voltage increment at thewidest part rll vide a compact V type antenna having a wider each of theconductors i 309110191136! bridged Patented Mar.2 6,19 40 t N E STAT SrArENr OFFIcE" h I Q LfWuZEEZVA SYSTEM 7 1 Radio Corporation of America,a corporation of Delaware a I Application April 8, 1938, ScriaYNm200,855 h I v a 1 J r -c1 as.. e1.250...33) a a This invention relatesto a directive antenna Still another object is to provide an antennasystem and, in particular, to directive antennae with a primarypeak-response for a particular which comprise as constituent elementsthereof vertical angle ofincidnce of the signal wave" of one Or more Vtype antennae. one frequency anda secondary peak response 5 An antennato which my invention is particuto a different vertical angle ofincidence of a larly adapted is the rhombic or diamond 2111- secondsignal wave of ayhigher frequency. tenna, one form of which is anarrangement A better understanding of my invention may with horizontalwires disposed a diamond, be had by reference tcthe following detailedshaped plan. The principle involved in such an 1 description -which isaccompanied by drawings I 10"" antenna is that the sidesare of suchlength that whereinFigure 1 shows an arrangement, accord 10 the signalcurrent will have to travel 180 degrees ing to the application abovereferred to, and of: further in the wires than'is traveled bythesigwhich my arrangement is an improvement, nal wave front which inducesthe increment of while FigureZ shows my improvement which jvolt ge inthe wires. AS ant nna 0f t yp provides for increased efficiency athigher fre t are ordinarily constructed the electrical velocityquencies." Figure 3 shows a practicable th 15 in the Wires isapproximately that Of the p d of effecting the principles of thisdisclosure, be of li ht or e sa e as e speed of p p n ing an enlargedview of a portion of Figure 2. of the electro-magnetic wave front oftheasig pi u '4, 5 6 h modifications of my nal. It is, therefore,necessary to either make t n, l the width of the structure great or thesides a It 5 known that the Velocity of pr'opar f of lengths in n thorder 3 gation along any current-carrying conductor Obtain the definedPhase relailomhlp- It 5*. system in space is substantially that of lightOften inconvenient to have the antenna i swaves. This is true for, asingle wire system as ture occupy so much territory and, furthermore;Well s a system b n more Wires 219 if the distance between the wires istoo great a in mp r The arrangement shown in Figure random Phasedisplacement between h Voltages 1 has a velocity lower than-that oflight by virtue induced the Wires may reduce 5 from of the fact that theloading members I carry the antmlpa'ted 1 r l y substantially nocurrent."

In the co'pendmg apphcatlonlNo" filed Figure 2 is similar to Figure lwith the addition of condensers 2 at the free ends of loading members I.The object of these condensers is to allow current to flowthroughloading members I at highfrequencies, thus increasing the velocity ofpropagation of, the system over that pre 3 vailing a-t-the lowerfrequencies, Thus a new I higher optimum frequency is provided. Thisfrequency is determined by the dimensions of the antenna and thevelocity of light, being that for which the voltage increment atA,traveling along theantenna to B at nearly the velocity of light, lagsthe voltageincrement at B by 180 degrees. v

Figure 3 showsin enlarged detail the construction of the antennaconductors. The load- 45. of the antenna with respect to the incrementmg m? I are connected m genes a transmitted to that point from the'endof the group f su or ia d e d st C011- antenha alone. wires; 1 V ductoris attached to the main aer al conductor b Ah object, therefore, of myinvention to prod by means of members 4,: At the other end of to theassignee of this application, there are shown methods whereby optimumsignal build up may be obtained in a rhombi-c' or diamond am tenna ofreduced dimensions by loading the anrent propagation along the antennaisreducecl from thenormalfree space value, Above the" optimum frequencyof such an antenna the re sultant voltage built up along the wholeantenna m idecreases. I

The present disclosure provides means for maintaining the antenna athigh ciiicien'cy at" frequencies above the optimum frequency asdetermined by the condition of ISOd'egreesphase' frequency response thangenerally obtainable acmss fro-the main aerial Wnductoli F W111 beheretofore. L Q seen from this figure that the auxiliary con- Anotherobject is to increase the velocity 0f ductors which areused to decreasethe speed of signal waves of higher frequency over that prethe wavealong the a'ntennawires may be conivailing at the optimum frequency. xveniently supported" from the mam antenna 55 structure without thenecessity of complicated supporting or guying structures.

Figure 4 shows a modification of my invention wherein two diamond shapedantennae are connected in parallel in order to increase the horizontaldirectivity of the antenna system.

Figure 6 shows another modification including two diamond shapedantennae which are, however, in this case connected in series.

Figure '7 shows a combination of the parallel connection of Figure 4withthe series connection of Figure 6, thereby increasing the signalresponse. The construction of the loading conductors in each of thesemodifications is the same as shown in Figure 3.

Figure 5 illustrates the application of my improvement to the V shapedantenna such as that shown by P. S. Carter. in Patent No. 1,974,387,dated September 18, 1934.

It is possible to proportion an antenna according to the aboveprinciples so that for-the lower optimum frequency maximum voltagebuild-uptakes place for a particular vertical angle of the signal wave,while for the higher optimum frequency maximum voltage build-up occursfor a different vertical angle. Thus, for example, if desired, a lowfrequency vertical angle in the neighborhood of 20 degrees may beprovided for,

while for the high frequency response a vertical angle of 10 to 15degrees may be chosen. This may be illustrated by an example, aspresented below.

Assume that it is desired to receive a signal frequency of '20 Mc/s.,arriving at an angle to the ground of 10, and also to receive a signalfrequency of 10 Mc/s., arriving at an angle of 15 to the ground and fromthe same horizontal direction; also assume the maximum available spacein the direction of the arriving signal is 200 meters, shown as L inFigure 2. At 20 Mc/s. the antenna may be proportioned on the basis ofvelocity of signal travel in the wires being substantially the velocityof light, so that one-half Wavelength difference exists betweenthetravel of the waves in the sides of the antenna and in space, or

6% (cos 10 1.05981 from which ==70.7 s in Figure 2) The velocity ofpropagation in the antenna wires necessary to give optimum signalbuild-up for the 10 Mc/s. signal isthen found as follows:

Let 1) denote the ratio of velocity of propagation in the antenna tothat in free space. Then for optimum signal,

That is, a velocity in the wires of approximately that in free space isrequired. This will enable the proper design of the loading sections tobe determined.

In a like manner, the proper design for any desired operating conditionsmay be determined.

While I have indicated and described particular arrangements forcarrying my invention into effect, my invention is by no means limitedto the particular arrangement shown and described and modifications maybe made without departing from the scope and the spirit of theinvention. I

I claim: 1. In an aerial system, an antenna conductor, radio apparatuscoupled to one end of said "antenna conductor, reactance elementscoupled of waves having a frequency higher than the said optimum isincreased.

2. An aerial comprising a plurality of conductors disposed in agenerally V shaped plan, a receiver coupled to the vertex of said aerialand reactance elements coupled at spaced points along each conductor ofsaid aerial for decreasing the velocity of propagation of a signal waveof an optimum frequency along the conductor as compared with thevelocity of propagation of said wave in space, said reactance elementseach comprising a relatively short conductor having one end connected tosaid aerial conductor and having a condenser connected between the otherend and said aerial conductor whereby the velocity of propagation ofwaves having a frequency higher than said optimum is increased.

3. An antenna. system in the form of a rhomhus and comprising fourconductors of substantially similar length located in the same plane, areceiver coupled toone vertex of. said antenna, an impedance networkconnected to the opposite vertex of said antenna which is equal to thesurge impedance of said antenna, and reactance elements connected atspaced points along each conductor of said antenna for decreasing thevelocity of propagation of a signal wave of an optimum frequency alongthe conductor as compared with the velocity of propagation of said wavein space, said. reactance elements each com prising a relatively shortconductor having one end connected to said antenna conductors and havinga condenser connected between the other end and said antenna conductorwhereby the velocity of propagation of Waves having a he quency higherthan said optimum is increased.

4. An antenna system comprising a pair of diamond shaped antennae, eachantenna com prising four conductors of substantially similar lengthlocated in the same plane, means for connecting the conductors at onevertex of each of saidantennas together, a receiver coupled tosaidmeans, an. impedance network connected to the oppositevertex of eachof said antennae which is equal to the surge impedance of the antennaassociated therewith and reactance elements'coupled at spaced pointsalong each conductor of each of said antenna for increasing the velocityof propagation of a signal wave of an optimum frequency along theconductors as compared with the velocity of propagation of said Wave inspace, said reactance elements each comprising a relatively short,conductor having one end connected to said antenna conductors and havinga condenser connected between the other end and said antenna conductorwhereby the velocity of propagation of waves having a frequency higherthan said optimum is increased.

'5. An antenna system comprising a pair of diamond shaped antennafeachantenna comprising four conductors of substantially similar lengthlocated in the same plane, means for connecting one vertex of oneantenna to one vertex of the other antenna, a receiver coupled to theother vertex of one of said antenna, an impedance network connected tothe remaining vertex which is equal to the surge impedance, of saidantennae and reactance elements coupled at spaced points along eachconductor of each or i said antenna for decreasingthe velocity ofpropagation of a signal wave of a predetermined optimum frequency alongeach conductor as compared with the velocity of propagation of said wavein. space, said reactance elements each comprising a relatively shortconductor having one end connected to said antenna conductor and havingacondenser connected between the other end and said antenna conductorwhereby the velocity of propagation of waves having a frequency higherthan said optimum is increased.

6. In an aerial system, an antenna conductor,

radio apparatus coupled to one endol said antenna conductor, reactanceelements coupled at spaced points along said conductor for decreasingthe velocity of propagation of a signal wave of ducto-rs disposed in agenerally V-shaped plan, a

receiver coupled to the vertex of said aerial, and reactance elementscoupled at spaced points along each conductor of said aerial for:decreasing the velocity of propagation of a signal wave of an optimumfrequency along the conductor as compared with the velocity ofpropagation of said wave in space, said reactance elements eachcomprising a relatively short conductor disposed parallel to. saidantenna conductors and having its end nearest said receiver connected tosaid aerial conductor and having a condenser connected between its endremote from said receiver and said aerial conductor whereby the velocityof propagation of waves having a frequency higher than said optimum isincreased.

8. An antenna system in the form of a rhombus and comprising fourconductors of substantially similar length located in the same plane, areceiver coupled to one vertex of said antenna, an impedance networkconnected to the opposite vertex of said antenna which is equal to thesurge impedance of said antenna, and reactance elements connected atspaced points along each conductor of said antenna for decreasing thevelocity of propagation of a signal wave of an optimum frequency alongthe conductor as compared with the velocity of propagation of said wavein space, said reactance elements each comprising a relatively shortconductor disposed parallel to said antenna conductor and having its endnearest said receiver connected to said aerial conductor and having acondenser connected between the end remote from said receiver and saidaerial conductor whereby the velocity of the propagation of waves havinga frequency higher than the said optimum is increased.

9. Anantenna system comprising a pair of diamond shaped antennae, eachantenna comprising four conductors of substantially similar lengthlocated in the same plane, means for connecting the conductors at onevertex of each of said antennas together, a receiver coupled to saidmeans,,an impedance network connected to the opposite vertex of each ofsaid antennae which is equal to the surge impedance of the antennaassociated therewith and reactance elements coupled at spaced pointsalong each conductor of each of said antenna for increasing the velocityof propagationof a signal wave of an optimum frequency along theconductors as compared with the velocity of propagation of said wave inspace, said reactance elements each comprising a relatively shortconductor disposed parallel to said antenna conductor and having its endnearest said receiver connected to said.

aerial conductor and. having a condenser connected between the endremote from said receiver and saidaerial conductor whereby the velocityof the propagation of waves having a frequency higher than the saidoptimum is increased.

10. An antenna system comprising a pair of diamond shaped antenna, eachantenna comprising four conductors of substantially similar lengthlocated in the same plane, means for vertex of the other antenna, areceiver coupled to the other vertex of one of said antenna, animpedance network connected to the remaining vertex which is equal tothe surge impedance of said antennae and reactance elements coupled atspaced points along each conductor of each or said antenna fordecreasing the velocity of propagation of a signal wave of apredetermined optimum frequency along each conductor as compared withthe velocity of propagationof said wave in space, said reactanceelements each I connected between the end remote from. saidreceiver andsaid aerial conductor whereby the velocity of thepropagation of waveshaving a:

frequency higher than the said optimum is increased.

MARTIN KATZIN.

